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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * processor_driver.c - ACPI Processor Driver
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <[email protected]>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
7 * Copyright (C) 2004 Dominik Brodowski <[email protected]>
8 * Copyright (C) 2004 Anil S Keshavamurthy <[email protected]>
9 * - Added processor hotplug support
10 * Copyright (C) 2013, Intel Corporation
11 * Rafael J. Wysocki <[email protected]>
12 */
13
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/cpufreq.h>
18#include <linux/cpu.h>
19#include <linux/cpuidle.h>
20#include <linux/slab.h>
21#include <linux/acpi.h>
22
23#include <acpi/processor.h>
24
25#include "internal.h"
26
27#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
28#define ACPI_PROCESSOR_NOTIFY_POWER 0x81
29#define ACPI_PROCESSOR_NOTIFY_THROTTLING 0x82
30#define ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED 0x85
31
32MODULE_AUTHOR("Paul Diefenbaugh");
33MODULE_DESCRIPTION("ACPI Processor Driver");
34MODULE_LICENSE("GPL");
35
36static int acpi_processor_stop(struct device *dev);
37
38static const struct acpi_device_id processor_device_ids[] = {
39 {ACPI_PROCESSOR_OBJECT_HID, 0},
40 {ACPI_PROCESSOR_DEVICE_HID, 0},
41 {"", 0},
42};
43MODULE_DEVICE_TABLE(acpi, processor_device_ids);
44
45static struct device_driver acpi_processor_driver = {
46 .name = "processor",
47 .bus = &cpu_subsys,
48 .acpi_match_table = processor_device_ids,
49 .remove = acpi_processor_stop,
50};
51
52static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
53{
54 struct acpi_device *device = data;
55 struct acpi_processor *pr;
56 int saved, ev_data = 0;
57
58 if (device->handle != handle)
59 return;
60
61 pr = acpi_driver_data(device);
62 if (!pr)
63 return;
64
65 switch (event) {
66 case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
67 saved = pr->performance_platform_limit;
68 acpi_processor_ppc_has_changed(pr, 1);
69 ev_data = pr->performance_platform_limit;
70 if (saved == ev_data)
71 return;
72
73 break;
74 case ACPI_PROCESSOR_NOTIFY_POWER:
75 acpi_processor_power_state_has_changed(pr);
76 break;
77 case ACPI_PROCESSOR_NOTIFY_THROTTLING:
78 acpi_processor_tstate_has_changed(pr);
79 break;
80 case ACPI_PROCESSOR_NOTIFY_HIGEST_PERF_CHANGED:
81 cpufreq_update_limits(pr->id);
82 break;
83 default:
84 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
85 return;
86 }
87
88 acpi_bus_generate_netlink_event("processor", dev_name(&device->dev),
89 event, ev_data);
90}
91
92static int __acpi_processor_start(struct acpi_device *device);
93
94static int acpi_soft_cpu_online(unsigned int cpu)
95{
96 struct acpi_processor *pr = per_cpu(processors, cpu);
97 struct acpi_device *device;
98
99 if (!pr)
100 return 0;
101
102 device = acpi_fetch_acpi_dev(pr->handle);
103 if (!device)
104 return 0;
105
106 /*
107 * CPU got physically hotplugged and onlined for the first time:
108 * Initialize missing things.
109 */
110 if (!pr->flags.previously_online) {
111 int ret;
112
113 ret = __acpi_processor_start(device);
114 WARN(ret, "Failed to start CPU: %d\n", pr->id);
115 } else {
116 /* Normal CPU soft online event. */
117 acpi_processor_ppc_has_changed(pr, 0);
118 acpi_processor_hotplug(pr);
119 acpi_processor_reevaluate_tstate(pr, false);
120 acpi_processor_tstate_has_changed(pr);
121 }
122 return 0;
123}
124
125static int acpi_soft_cpu_dead(unsigned int cpu)
126{
127 struct acpi_processor *pr = per_cpu(processors, cpu);
128
129 if (!pr || !acpi_fetch_acpi_dev(pr->handle))
130 return 0;
131
132 acpi_processor_reevaluate_tstate(pr, true);
133 return 0;
134}
135
136#ifdef CONFIG_ACPI_CPU_FREQ_PSS
137static void acpi_pss_perf_init(struct acpi_processor *pr)
138{
139 acpi_processor_ppc_has_changed(pr, 0);
140
141 acpi_processor_get_throttling_info(pr);
142
143 if (pr->flags.throttling)
144 pr->flags.limit = 1;
145}
146#else
147static inline void acpi_pss_perf_init(struct acpi_processor *pr) {}
148#endif /* CONFIG_ACPI_CPU_FREQ_PSS */
149
150static int __acpi_processor_start(struct acpi_device *device)
151{
152 struct acpi_processor *pr = acpi_driver_data(device);
153 acpi_status status;
154 int result = 0;
155
156 if (!pr)
157 return -ENODEV;
158
159 result = acpi_cppc_processor_probe(pr);
160 if (result && !IS_ENABLED(CONFIG_ACPI_CPU_FREQ_PSS))
161 dev_dbg(&device->dev, "CPPC data invalid or not present\n");
162
163 acpi_processor_power_init(pr);
164
165 acpi_pss_perf_init(pr);
166
167 result = acpi_processor_thermal_init(pr, device);
168 if (result)
169 goto err_power_exit;
170
171 status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
172 acpi_processor_notify, device);
173 if (!ACPI_SUCCESS(status)) {
174 result = -ENODEV;
175 goto err_thermal_exit;
176 }
177 pr->flags.previously_online = 1;
178
179 return 0;
180
181err_thermal_exit:
182 acpi_processor_thermal_exit(pr, device);
183err_power_exit:
184 acpi_processor_power_exit(pr);
185 return result;
186}
187
188static int acpi_processor_stop(struct device *dev)
189{
190 struct acpi_device *device = ACPI_COMPANION(dev);
191 struct acpi_processor *pr;
192
193 if (!device)
194 return 0;
195
196 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
197 acpi_processor_notify);
198
199 pr = acpi_driver_data(device);
200 if (!pr)
201 return 0;
202 acpi_processor_power_exit(pr);
203
204 acpi_cppc_processor_exit(pr);
205
206 acpi_processor_thermal_exit(pr, device);
207
208 return 0;
209}
210
211bool acpi_processor_cpufreq_init;
212
213static int acpi_processor_notifier(struct notifier_block *nb,
214 unsigned long event, void *data)
215{
216 struct cpufreq_policy *policy = data;
217
218 if (event == CPUFREQ_CREATE_POLICY) {
219 acpi_thermal_cpufreq_init(policy);
220 acpi_processor_ppc_init(policy);
221 } else if (event == CPUFREQ_REMOVE_POLICY) {
222 acpi_processor_ppc_exit(policy);
223 acpi_thermal_cpufreq_exit(policy);
224 }
225
226 return 0;
227}
228
229static struct notifier_block acpi_processor_notifier_block = {
230 .notifier_call = acpi_processor_notifier,
231};
232
233void __weak acpi_processor_init_invariance_cppc(void)
234{ }
235
236/*
237 * We keep the driver loaded even when ACPI is not running.
238 * This is needed for the powernow-k8 driver, that works even without
239 * ACPI, but needs symbols from this driver
240 */
241static enum cpuhp_state hp_online;
242static int __init acpi_processor_driver_init(void)
243{
244 int result = 0;
245
246 if (acpi_disabled)
247 return 0;
248
249 if (!cpufreq_register_notifier(&acpi_processor_notifier_block,
250 CPUFREQ_POLICY_NOTIFIER)) {
251 acpi_processor_cpufreq_init = true;
252 acpi_processor_ignore_ppc_init();
253 }
254
255 acpi_processor_register_idle_driver();
256
257 result = driver_register(&acpi_processor_driver);
258 if (result < 0)
259 goto unregister_idle_drv;
260
261 result = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
262 "acpi/cpu-drv:online",
263 acpi_soft_cpu_online, NULL);
264 if (result < 0)
265 goto err;
266 hp_online = result;
267 cpuhp_setup_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD, "acpi/cpu-drv:dead",
268 NULL, acpi_soft_cpu_dead);
269
270 acpi_processor_throttling_init();
271
272 /*
273 * Frequency invariance calculations on AMD platforms can't be run until
274 * after acpi_cppc_processor_probe() has been called for all online CPUs
275 */
276 acpi_processor_init_invariance_cppc();
277
278 acpi_idle_rescan_dead_smt_siblings();
279
280 return 0;
281
282err:
283 driver_unregister(&acpi_processor_driver);
284
285unregister_idle_drv:
286 acpi_processor_unregister_idle_driver();
287
288 if (acpi_processor_cpufreq_init) {
289 cpufreq_unregister_notifier(&acpi_processor_notifier_block,
290 CPUFREQ_POLICY_NOTIFIER);
291 acpi_processor_cpufreq_init = false;
292 }
293
294 return result;
295}
296
297static void __exit acpi_processor_driver_exit(void)
298{
299 if (acpi_disabled)
300 return;
301
302 if (acpi_processor_cpufreq_init) {
303 cpufreq_unregister_notifier(&acpi_processor_notifier_block,
304 CPUFREQ_POLICY_NOTIFIER);
305 acpi_processor_cpufreq_init = false;
306 }
307
308 cpuhp_remove_state_nocalls(hp_online);
309 cpuhp_remove_state_nocalls(CPUHP_ACPI_CPUDRV_DEAD);
310 driver_unregister(&acpi_processor_driver);
311 acpi_processor_unregister_idle_driver();
312}
313
314module_init(acpi_processor_driver_init);
315module_exit(acpi_processor_driver_exit);
316
317MODULE_ALIAS("processor");